<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>404</title>
    <style>
        /* 基础样式 */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
        }
        
        body {
            background-color: #f5f7fa;
            color: #333;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            padding: 20px;
            text-align: center;
        }
        
        /* 容器样式 */
        .container {
            max-width: 600px;
            width: 100%;
            padding: 60px 30px;
            border-radius: 12px;
            /* background: white; */
            /* box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1); */
            transform: translateY(-20px);
            animation: fadeUp 0.6s ease-out forwards;
        }
        
        /* 数字样式 */
        .error-number {
            font-size: 120px;
            font-weight: 900;
            color: #3498db;
            margin-bottom: 20px;
            position: relative;
            display: inline-block;
        }
        
        .error-number::before,
        .error-number::after {
            content: '';
            position: absolute;
            width: 100%;
            height: 100%;
            top: 0;
            left: 0;
            background: #3498db;
            opacity: 0.1;
            border-radius: 50%;
            transform: scale(0.8);
            z-index: -1;
            animation: pulse 2s infinite;
        }
        
        .error-number::after {
            animation-delay: 0.5s;
        }
        
        /* 标题和内容样式 */
        h1 {
            font-size: 28px;
            margin-bottom: 15px;
            color: #2c3e50;
        }
        
        p {
            font-size: 16px;
            color: #7f8c8d;
            margin-bottom: 30px;
            line-height: 1.6;
        }
        
        /* 按钮样式 */
        .btn {
            display: inline-block;
            padding: 12px 28px;
            background-color: #3498db;
            color: white;
            text-decoration: none;
            border-radius: 30px;
            font-size: 16px;
            font-weight: 600;
            transition: all 0.3s ease;
            border: none;
            cursor: pointer;
            box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3);
        }
        
        .btn:hover {
            background-color: #2980b9;
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(52, 152, 219, 0.4);
        }
        
        .btn:active {
            transform: translateY(0);
        }
        
        /* 页脚样式 */
        footer {
            margin-top: 30px;
            font-size: 14px;
            color: #95a5a6;
        }
        
        /* 动画定义 */
        @keyframes fadeUp {
            to {
                transform: translateY(0);
                opacity: 1;
            }
        }
        
        @keyframes pulse {
            0% {
                transform: scale(0.8);
                opacity: 0.1;
            }
            50% {
                transform: scale(1);
                opacity: 0.2;
            }
            100% {
                transform: scale(0.8);
                opacity: 0.1;
            }
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .container {
                padding: 40px 20px;
            }
            
            .error-number {
                font-size: 90px;
            }
            
            h1 {
                font-size: 24px;
            }
            
            p {
                font-size: 14px;
            }
            
            .btn {
                padding: 10px 24px;
                font-size: 14px;
            }
        }
        
        @media (max-width: 480px) {
            .error-number {
                font-size: 70px;
            }
            
            h1 {
                font-size: 20px;
            }
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="error-number">404</div>
        <h1>抱歉，您访问的页面不存在</h1>
        <p>您可能输入了错误的地址，或者该页面已被移除。请检查您的URL是否正确，或者返回首页继续浏览。</p>
        <a href="/" class="btn">返回首页</a>
    </div>
    <footer>
        © 2023 Smart HTTP Proxy 服务
    </footer>
</body>
</html>